Mathematics

Seminar

Rocky Mountain Algebraic Combinatorics Seminar

Upcoming Seminars Schedule

A representation theory for tensors

Sean Willmot
Colorado State University

We use standard homogeneous module theory as a basis for constructing a heterogeneous generalization as it applies to tensors. In particular, we start by redefining modules, representations, and several related concepts in terms of bilinear maps and then develope basic category theoretic language for handling them. This leads to the discovery of multiple heterogeneous objects which do not have a proper homogeneous analog. We then develope the tools for addressing a heterogeneous Frobenius Reciprocity Theorem, including the concepts of restriction and induction, and apply these to recover part of this theorem as it pertains to bilinear maps.

On the automorphism group of a putative Conway 99-graph

Patrick Cesarz
University of Wyoming

Let Γ be a Conway 99-graph, that is, a strongly regular graph with parameters (99,14,1,2). Makhnev and Minakova prove that the automorphism group G of Γ must have order dividing 2 ·33 ·7 ·11. They further show that if |G| is divisible by 2 then |G| must divide 42. Subsequently Behbahani and Lam prove that the only prime divisors of |G| are 2 and 3. However their results depended heavily on the aid of a computer. In this talk we discuss how we were able to obtain computer-free proofs that establish that divisibility by 7 implies G ≅ Z₇. As a consequence, divisibility by 2 implies |G| divides 6, i.e. G is isomorphic to one of Z₂, Z₆, S₃.

Weber 223
4–6 pm
Friday, April 5, 2024
(Refreshments 3:30–4 pm)
Colorado State University

This is a joint Denver U / UC Boulder / U of Wyoming / CSU seminar that meets biweekly. Anyone interested is welcome to join us at a local restaurant for dinner after the talks.

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Previous Seminars:

March 22, 2024: John Jasper, John Jasper
February 23, 2024: Ewan Davies, Ewan Davies
February 9, 2024: Charlotte Aten, Paul Horn
January 26, 2024: James Wilson, James Wilson
November 17, 2023: Maria Gillespie, Kyle Salois
November 3, 2023: Ben Young, Ben Young
October 10, 2023: Amit Patel, Amit Patel
September 22, 2023: Joseph Pappe, Joseph Pappe
September 8, 2023: Peter Patzt, Peter Patzt
August 25, 2023: Bernhard Bodmann, Bernhard Bodmann
April 21, 2023: Angela Carnevale, Angela Carnevale
April 14, 2023: Tobias Rossmann, Tobias Rossmann
March 3, 2023: John Griesmer, John Griesmer
February 17, 2023: Douglas McKenna, Dheer Desai
February 3, 2022: Richard Green, Richard Green
Nov 18, 2022: Martha Precup,
Nov 4, 2022: Martin Kassabov, Martin Kassabov
Oct 28, 2022: Aram Bingham, Aram Bingham
October 3, 2022: Nathan Lindzey, Nathan Lindzey
Sept 30, 2022: Mandi Schaeffer Fry, Jay Taylor
Sept 16, 2022: Henry Adams,
May 6, 2022: Emily King, Lucas Gagnon
Apr 8, 2022: Michael Levet,
Apr 7, 2022: Willen De Graaf,
Dec 2, 2021: Leonard Soicher,
Dec 3, 2021: Foster Tom,
Oct 28, 2021: Simon Blackburn,
Oct 15, 2021: Khanh Nguyen,
Oct 15, 2021: Khanh Nguyen,
Oct 1, 2021: Mikl\'os B\'ona, Mei Yin
Sep 17, 2021: Nathan Lindzey, James Wilson
Sep 3, 2021: Sean Griffin, Maria Gillespie
May 7, 2021: Harley Meade,
April 23, 2021: Jonah Blasiak,
April 9, 2021: Kenneth McLaughlin,
March 12, 2021: Marni Mishna,
February 26, 2020: Justin Lynd,
February 12, 2020: Michael Epstein,
December 4, 2020: Fatma Karaoglu,
November 13, 2020: James Wilson, James Wilson
October 30, 2020: Shawn Burkett, Wencin Poh
October 16, 2020: Edinah K. Gnang, Alexander Hulpke
September 18, 2020: Aram Dermenjian,
September 18, 2020: Aram Dermenjian,
August 14 2020: Federico Castillo,
July 24 2020: James Wilson,
July 10 2020: Nathan Lindsey,
June 12, 2020: Maria Gillespie,
May 29, 2020: Henry Adams,
May 8, 2020: Dustin Mixon,
Apr 24, 2020: Peter Cameron,
Apr 3, 2020: Alexander Hulpke,
Feb 28, 2019: Joseph Iverson, John Jasper
Jan 24, 2019: Jonathan Novak,
Dec 6, 2019: Brendon Rhoades, James Wilson
Nov 15, 2019: Joshua Grochow, Maria Gillespie
Nov 1, 2019: Eilidh McKemmie, Michael Epstein
Oct 11, 2019: Martin Kassabov, Eric Moorhouse
Sep 27, 2019: Alexander Hulpke, Tianjuan Xu
Sep 13, 2019: Laura Scull, Emily King
Sep 28, 2018: Farid Aliniaeifard, Brady Tyburski
Sep 7, 2018: James Wilson, Alexander Hulpke
Apr 20, 2018: Maria Monks Gillespie, Alistair Savage
Apr 6, 2018: Susan Hermiller, Nathaniel Thiem
March 23, 2018: Henry Tucker, Richard Green
March 2, 2018: Nik Ruskuc, Joshua Grochow
February 16, 2018: Hamidreza Chitsaz, Mark Lewis
February 2, 2018: James B. Wilson, Anton Betten
November 10, 2017: Michael Kinyon, Petr Vojt\v{e}chovsk\'y
October 20, 2017: Eric Moorhouse, William DeMeo
October 6, 2017: Spencer Gerhardt, Joshua Grochow
September 22, 2017: Amanda Schaeffer Fry, Henry Kvinge
September 8, 2017: Peter Mayr, James B. Wilson
May 5, 2017: Ferdinand Ihringer, Gavin King
April 21, 2017: Vladimir D. Tonchev, Morgan Rodgers
April 7, 2017: Jason Williford, Anton Betten
March 24, 2017: Isabella Novik, Peter Brooksbank
March 3, 2017: Jintai Ding, Curtis Bennett
February 17, 2017: Fatma Karaoglu, Eric Moorhouse
February 3, 2017: Tim Penttila, James B. Wilson
December 2, 2016: Jim Fowler, Andrew Kelley
November 11, 2016: Joseph Gersch, Joshua Maglione
October 28, 2016: John MacLaren Walsh, Henry Adams
October 14, 2016: JM Landsberg, James B. Wilson
September 30, 2016: Alexander Hulpke, Oscar Levin
September 16, 2016: Delaram Kahrobaei, Amit Patel
June 23, 2016: Jason Cantarella, Michal Adamaszek
April 29, 2016: Nick Loehr, Jason Williford
April 15, 2016: Alexander Hulpke, Klaus Lux
April 1, 2016: Eamonn O'Brien, Izabella Stuhl
February 19, 2015: James Wilson, Anton Betten
December 4, 2015: Maria Monks Gillespie, Dane Flannery
November 13, 2015: Richard Green, Tim Penttila
October 23, 2015: Christina Boucher, Sylvia Hobart
October 9, 2015: Josh Maglione, Ghodratollah Aalipour
September 25, 2015: Ross McConnell, Henry Adams
September 11, 2015: James B. Wilson, Tim Penttila
May 8, 2015: Amanda Schaeffer Fry, Peter Brooksbank
April 24, 2015: Heide Gluesing-Luerssen, Phil DeOrsey
March 6, 2015: Felice Manganiello, Eric Moorhouse
February 20, 2015: Anton Dzhamay, Anton Betten
February 6, 2015: Alexander Hulpke, Morgan Rodgers
December 5, 2014: Stefaan De Winter, Gretchen Matthews
November 14, 2014: Greg Coxson, Tom Dorsey
October 31, 2014: Octavio Paez Osuna, Sylvia Hobart
October 10, 2014: Takunari Miyazaki, Eric Moorhouse
September 26, 2014: Elissa Ross, Anton Betten
September 12, 2014: Petr Vojtěchovský, Alexander Hulpke
May 9, 2014: Philip DeOrsey, Tim Penttila
April 25, 2014: William J Martin, Jason Williford
April 11, 2014: Victor Pambuccian, George Shakan
March 7, 2014: Nathan Lindzey, Jens Harlander
February 21, 2014: Ross McConnell, Anton Betten
November 22, 2013: Justin Hughes, Josh Maglione

Department of Mathematics
Fort Collins, Colorado 80523